1. Field of the Invention
The present invention relates generally to compression splints for trauma and, more particularly, to a semi-rigid pelvic compression splint.
2. Prior Art
Pelvic compression splints of the prior art are typically fabricated from a solid piece of fabric or other material. While these splints have their advantages in order to ensure that the providers can see and access the anterior abdomen, pelvis, and ano-genital regions, the splint must be disengaged. Furthermore, these pelvic compression splints of the prior art cause compressive forces to be applied to the soft anterior abdominal/pelvic wall and not to the bony pelvis itself where it is most needed.
Each device that is used to compress and stabilize the pelvis has unique attributes and flaws. The principal devices in common use are the military and anti-shock trousers (MAST pants), and a variety of external frames that use pins to attach to the pelvis. The semi-rigid pelvic compression splint of the present invention is designed to combine the non-invasiveness and adjustability of the MAST garment with the medially-directed compression vectors and limb, femoral and anterior abdomino-pelvic exposure of the C-clamp, Pelvic Stabilizer and External Fixator.
MAST pants (military anti-shock trousers or the PASG (pneumatic anti-shock garment) were first used in the Vietnam era for shock resulting from military injuries. They are nylon pant suits with inflatable compartments. They are fit around the patient""s legs and torso and extend from the ankle to the lower rib cage. They are closed with Velcro and the inflatable compartments are filled from inferior to superior. There are compartments running up the circumference of each leg, and a large compartment is located over the anterior pelvis and abdomen that extends to the rib cage. The original purpose of the MAST pants was to force blood out of the extremities, pelvis and lower abdomen and into the central circulation supplying the brain and cardiopulmonary system. This process was referred to as xe2x80x9cauto-transfusionxe2x80x9d, and it was initially believed that the pants worked through this mechanism to restore effective central circulation volume and save lives. It is now believed that blood pressure increases related to the MAST pants result from increased afterload, and that the increased intra-abdominal pressure generated by the MAST pants may xe2x80x9ctheoreticallyxe2x80x9d reduce some bleeding in this area.
Whatever their affects on hemodynamics, the use of MAST pants has been called into question during the last ten years. Studies have shown that the device does not decrease morbidity and mortality in trauma-related hemorrhagic shock, and that it may be detrimental to patients with associated chest trauma. As a result, the routine use of MAST pants by EMS units has been largely phased out in the United States. Fortuitously, as this de-emphasis of MAST-pants application occurred, they were found to be effective in stabilizing and compressing the fractured pelvis in the EMS and ED setting. As a result MAST pants have had a second life as a limited part of certain pre-hospital and emergency department pelvic trauma resuscitation protocols.
Unfortunately, use of the MAST pants in the pelvic fracture is limited by their many disadvantages. They are only sparingly used in America and a 1995 study reported that only about 10% to 20% of British trauma centers used them, respectively, for pre-hospital and in-patient care. There are many reasons for this. They are somewhat difficult to place on a patient because they cover such a large part of the body, have many closures, and must be completely opened before the patient can be placed in them. Once the pants are fitted, they cover the entire area of the lower limbs, pelvis and abdomen up to the rib cage. The coverage of the legs is unwanted because it prevents assessment of the lower limbs, and compression of the lower limbs has been found to cause compartment syndromes.
Even if MAST pants could be used without attaching the leg pieces, the abdomino-pelvic component would still obscure the entire abdomino-pelvic region up to the rib cage. As noted above, restricting visibility and access to this area is a major disadvantage in trauma care because about half of all pelvic fracture patients also have serious intra-abdominal injuries that must be assessed in a timely fashion. These problems are further complicated by the fact that opening the pants must be done very slowly because there is often a large drop in blood pressure caused by the rapid decrease in afterload associated with garment removal.
Simply trimming MAST pants to a size that conforms to pelvic area would not make them ideal for pelvic compression and stabilizationxe2x80x94another shortcoming of the MAST pants is that the compression vector of the abdomino-pelvic component is anterior to posterior. The pants use a large anterior inflatable compartment that compresses the anterior abdomen, increasing intra-abdominal pressure and decreasing the volume of the abdomen and pelvis. Any medially-directed compression is secondary to the dominant anterior-posterior compressive force of the device. Primary AP compression is not optimal for achieving partial reduction, compression, and stabilization of sacro-iliac disruption and pubic symphysis diastasis, and all recently developed invasive external frames primarily employ medially-directed compression vectors. While increasing intra-abdominal pressure may have some theoretical benefit, it has more physiologic costs than medially-directed compression. Both human and animal studies have shown that MAST pants reduce diaphragmatic excursion and compromise respiratory mechanics in critically ill patients. They may also worsen left ventricular function, especially in those with pre-existing heart disease. In addition, AP compression compromises skin integrity over crucial anterior and posterior operative approaches to the pelvis, impeding definitive repair of the injury. Finally, there is no way to achieve anterior-posterior compression without completely obscuring at least part of the anterior abdomen and pelvis.
The history of the MAST pants is interesting in this light, because limb and AP compression over the soft anterior abdomino-pelvic wall does seem to be more likely to squeeze blood into the upper torso than medially directed compression of the relatively rigid contours of the bony pelvis. Unfortunately, as noted above, the autotransfusion/increased afterload function of the device has not been found to be effective for improving outcomes in trauma. The later discovery that the device is helpful in pelvic fractures was fortunate, but the fact that MAST pants were not designed for pelvic stabilization has given them numerous features (described above) that severely limit their use in the multiply-injured blunt trauma patient with a potential pelvic fracture.
The invasive external pelvic compression/stabilization devices of the prior art include the External Fixator, C-Clamp, and Pelvic Stabilizer. The term xe2x80x9cinvasivexe2x80x9d is used to mean that in order to use any of these devices, an orthopedic surgeon, or other specially trained provider must incise the patient""s skin, dissect through fascial and/or muscle layers and place a pin into the bony pelvis.
These devices were all designed to stabilize and compress the pelvis before definitive operative repair can be done. Unlike the MAST pants, they were designed for this purpose and primarily provide medially-directed compression of the pelvis while allowing the trauma team to have access to the abdomen and extremities. As briefly mentioned above, all work on the same principle: an external compression frame is connected to the pelvis by means of transcutanous pins that are surgically placed into the iliac wings or posterior ileum. The frame is then adjusted to compress/stabilize and possibly reduce the pelvic disruption. The frame itself can then be swung inferiorly or superiorly to facilitate access to the abdomen or lower limbs.
The frames themselves vary. The External fixator is generally favored for open book fractures with pubic symphysis diatheses. Its pins are placed in the iliac wings, and it is thought to be less useful in posterior disruptions of the sacroiliac joints. The Pelvic Stablizer is also pinned to the iliac wing but it is designed to be more useful than the EX-fix for SI joint disruption. The Pelvic Anti-Shock Clamp (C-Clamp) is pinned to the posterior ileum and it applies medially-directed compression to the sacro-iliac joint in order to stabilize posterior ring disruptions. Like the MAST pants, External Fixators have been shown to be effective in treating pelvic fractures. The posterior devices have only been used for a brief period of time, but both show promise in the stabilization of bony structures and control of hemorrhage.
The external compression frames have two major advantagesxe2x80x94they are effective in compressing pelvic fractures, and they allow unrestricted access to the abdomen or lower extremities. Despite this, use is severely limited by the need to have an orthopedic surgeon present who can dissect through skin and muscle and properly place a pin in bone. Obviously, the required time and talent for this procedure is not available in the pre-hospital context, and rarely if ever available in a community hospital that functions in the trauma system as a point for resuscitation, stabilization, and transfer.
Even at level one trauma centers, the invasive devices are rarely used. Even with the resources of level one trauma centers, multiple blunt trauma patients are difficult to stabilize. In the initial stages of management, work is concentrated on establishing an airway, obtaining adequate IV access, placing chest tubes, performing an adequate secondary survey, and obtaining basic radiographs. At this point there are usually too many people and too much going on around the bed to accommodate an orthopedic team that needs to closely inspect the pelvis, antiseptically prepare the skin over the pelvis, and place these devices. Later in the resuscitation the priority becomes determining if dangerous intra-abdominal or intracranial injuries are present. Finally, in the situation in which an external fixator or C-Clamp is desired, the in-house orthopedic staff often consists of residents who are not as highly skilled in performing the procedures as attending orthopedic traumatologists with expertise in this area. Even with skilled staff there would be other costs of placing the frames. There is a risk of pin tract infection complicating later open reduction and internal fixation, and time lost for other emergent procedures, such as diagnostic peritoneal lavage, CT scan, laparotomy and pelvic angiography.
Therefore, it is an object of the present invention to provide a semi-rigid pelvic compression splint for trauma that provides rapid, simple, non-invasive pre-hospital and ED compression and stabilization of pelvic injuries which is able to be partially assembled beforehand, slid under the patient, and rapidly closed anteriorly without obscuring abdominal and pelvic anatomy and injury.
It is also an object of the present invention to provide a semi-rigid pelvic compression splint for trauma that covers only an area of the body that needs to be stabilized in pelvic fractures and preserve access to the femoral triangles, lower limbs, and anterior pelvis and abdomen. Their adjustment and closeness of fit is a matter of tightening adjustable straps, placing foam-lined plastic splints against each lateral pelvis, and filling inflatable compartments.
The semi-rigid pelvic compression splint for Trauma is a new device that combines the best features of the MAST pants, External Fixator, Pelvic Anti-shock Clamp, and Pelvic Stabilizer. It is an inexpensive, completely non-invasive, rapidly-applied splint that will provide pelvic compression and stabilization at the sacro-iliac joint and the pubic symphysis. No specialized training is required to apply the splint, and it can be placed during pre-hospital, emergency department, OR or ICU care. Even when applied and fully engaged, the splint will allow visualization of and access to the ano-genital and femoral areas, anterior abdomen and pelvis, and lower limbs. It has no deleterious effects on cardio-pulmonary mechanics. The semi-rigid pelvic compression splint has an adjustable attachment and compression system, can be left in place during laparotomy, and is designed to minimize skin complications.
Relative to MAST pants, the semi-rigid pelvic compression splint of the present invention is designed to be easier and faster to place on the patient during the transport and resuscitation process. It allows the physician to see and access the anterior abdomen and pelvis, and provides the medially-directed compression vectors most likely to achieve stabilization, compression and partial reduction of pubic symphysis diastasis and sacro-iliac disruption (again, all the new invasive external frames provide primarily lateral to medial and not AP compression). It can be used in the ED, OR, CT or ICU environments, and is less likely than the MAST pants to cause skin breakdown over potential operative sites for definitive pelvic repair.
Accordingly, a pelvic compression splint for splinting support and compression of the pelvis is provided. The pelvic compression splint comprises: right and left support members to be positioned on the right and left sides, respectively, of the pelvis; and a support means for supporting the right and left support members compressively against the right and left sides of the pelvis.
Preferably the pelvic compression splint further comprises right and left cushions positioned between the right and left support members, respectively, and the right and left side of the pelvis. The right and left cushions preferably further have a concavity to fit the contours of the right and left sides of the pelvis, respectively. Preferably, at least one of the right and left cushions further comprises an inflatable compartment for applying further and varying compression against the right and left sides of the pelvis. The inflatable compartment preferably further comprises a pump and valve system for pressuring the inflatable compartment and releasing pressure therefrom, respectively.
The support means preferably comprises a sling fastened at each end to the support plates by a first plurality of straps, the support means further having a fastening means for maintaining the support plates and inner shells compressively against the right and left sides of the pelvis. The fastening means preferably comprises a second plurality of straps, each of the second plurality of straps having a fixing means for fixing the straps to each of the support plates.
In a preferred implementation of the semi-rigid compression splint, the same comprises: right and left plates to be positioned on the right and left sides, respectively, of the pelvis; right and left cushions positioned between the right and left plates, respectively, and the right and left side of the pelvis; and a support means for supporting the right and left plates and right and left cushions compressively against the right and left sides of the pelvis.